It’s really recommended to send your newsletters via a dedicate email service provider. One of the big players in this field is Amazon’s Simple Email Service (SES).
People signup to your newsletter – great. Not so great if they use none existing email addresses. While there’s no way to be 100% sure if a certain email address exists there’s a way to reduce false signups tremendously.
Currently are two free plugins available: Mailster Cool Captcha for Forms Mailster reCaptcha™ for Forms You can find the on them WordPress Plugin repo.
If you are running your own shop with WooCommerce and would like to get your customers as subscribers to your newsletter campaigns check out the WooCommerce add-on available for free on the WordPress repo.
With Mailster you get many details from your subscribers: clicks, opens, unsubscriptions and bounces. If you watch your websites visitors via an analytics system like Google Analytics or Piwik you can now track you newsletter campaigns with them too.